LIBRARY OF CONGRESS. 

Shelf ..(1^4. 



UNITED STATES OF AMERICA. 



:'f!? v 



A DESCRIPTION 



OF THE 



CROSBY 



Steam Engine Indicator, 



WITH DIRECTIONS FOR ITS USE, 



AXD 



A FEW GENERAL RULES FOR READING AND 
MEASURING DIAGRAMS. 

By GEORGE H. CROSBY. 



ALSO, 



-^0 



AN APPENDIX ; 



ENUMERATING SPECIALTIES MANUFACTURED 



CROSBY STEAM G AG E,j&--VA LVE GO. 

^0. SkX^J' 



' 1880. 










Copyright, 1880, 

BY 

Geohge H. Crosby 



MilU, Kniglit ^- Co., Printers, 115 Congress Street, Boston. 



INTRODUCTION 



In this pamphlet, which accompanies and intro- 
duces The Crosby Steam Engine Indicator, 
we desire to draw the attention of all persons 
interested in the steam engine to the great ad- 
vantages attending the use of this instrument, and 
to give such information as will enable any person 
to use it to the best advantage. It is not inteirded 
to be a treatise on the Indicator, but merely 
to present, in an intelligible form for practical 
use, a few facts which have been gleaned from 
various sources, namely: the invention of the first 
Indicator; its primitive condition; subsequent im- 
provements; as improved by Geo. H. Crosby in 
1879; what it is now capable of doing; how 
to do it; and what to do with it after using. 
There are also given a few explanations as to the 
diagram and formulas for calculating the power of 
the engine. For the benefit of those who desire 
to become more fully informed as to all that pertains 



4 INTRODUCTION. 

to the Indicator and the properly computed tables, 
reference is made to the following works : '^ The 
Steam Engine Indicator/^ by Chas. T. Porter; 
^•Elementary Treatise on Steam and the use of 
the Indicator/^ by J. C. Graham ; " Treatise on the 
Indicator and Dynamometer," by Thos. I. Main and 
Thos. Brown; "Engineering Popularized," byWm. 
Lee Church. 

GEORGE H. CROSBY. 

Crosby Steam Gage & Valve Co., 1880. 



THE STEAM ENGINE INDICATOR, 



The Steam Eno^ine Indicator is desiofned to 
register automatically upon paper the pressure 
of steam in the cylinder at every point of the 
piston's stroke. The form of the diagram thus 
drawn b}^ it affords information of a variety of 
facts not otherwise readily obtained. It must 
be remembered, however, that it tells nothing 
about the causes which have determined the 
form of the fioure which is described ; the 
operator concludes what these are by a process 
of reasoning based upon observation and expe- 
rience and some given data ; errors are here 
very liable to be committed, and the ability to 
arrive at accurate conclusions is of the greatest 
importance, and one of the highest attainments 
of an engineer. It is now universally conceded 
that the Indicator is an invalua1)le appendage to 
the steam engine, and when successfully applied 
and intelligently read, cannot be too highly 
estimated. The good condition and economy of 
every engine made or sold ought to be proved 



b THE STEAM ENGINE INDICATOR. 

by the Indicator diagram. In fact, no builders 
of first-class engines consider their canvass 
complete without showing a fac-simile of the 
diao'ram of their enoine. The advantao'e re- 

o O o 

sultino' from the use of this instrument, in 
point of economy, safety and power, is very 
great, and is recognized by the master mechanics 
and engineers thoughout the country. 



HISTORY OF THE INDICATOR. 

The invention of the Steam Engine Indicator 
is accredited to James Watt. It has undergone 
various modifications and improvements since 
his time. It was at first direct-acting, or, in 
other words, the pencil was attached directly 
to the piston-rod, and registered the motion of 
the same without multiplication ; and was only 
adapted for slow running engines. In this 
form it attained its highest point of excellence 
as manufactured by Wm. McNaught of Scot- 
land. (See cut No. 1.) The adoption of 
increased velocities of piston, with greater 
pressures of steam and higher grades of expan- 
sion, caused the long and tremulous spring used 
to oscillate violently by the momentum of the 



THE STEA31 ENGINE INDICATOR, 



piston and its connections, and gave as a 
a serrated fioiire, from 
which but little infor- 
mation could be extract- 
ed. At this time an 
Improved Steam Engine 
Indicator was invented 
by Chas. B. Richards. 
This Indicator had a 
short, strong spring, 
short motion of piston, 
combined with a lever 
and links for multiply- 
ing the motion of the 
piston and transmitting 
it to the pencil. These 
were the distino-uishino: 
features, and were de- 
signed to obviate the 
difficulties before men- 
tioned, but it was found 
still subject to grave 
errors of r egi st ration . 
The multiplication* of 
the motion of the piston 
was not uniform for all 
portions of the stroke ; 
the line of motion of 



result 




8 THE STEAM ENGINE INDICATOR. 

the pencil was not strictly parallel with the 
line of motion of the piston, describing not 
a straight line but only an elongated S. But 
it was a great stride in the right direction, and 
answered in the absence of anything better, until 
the still increasing velocities of piston out- 
stripped its capacity to register without ser- 
rated lines. (See Diag. No. 7.) This last fault, 
with its other defects, ^ade it imperative that 
a more reliable instrument should be made 
before correct indications could be procured. 

After considerable study and experiment, 
Mr. Crosby invented the Improved Parallel 
Motion Steam Engine Indicator, which obviates 
the above difficulties to a great extent, and 
superiority is claimed for this instrument for 
engines running at any velocity. 



DESCRIPTION OF THE CROSBY 
INDICATOR. 

The principle and action of Indicators are so 
simple, and to most practical engineers now 
so well understood, that it will only be neces- 
sary to give the following cut and description of 



THE STEAM ENGINE INDICATOR 



the parts of this instrument to readily appre- 
ciate the advantages accruing from its use. 




No. 2. 



The Crosby Steam Ewjine Indicator, 



10 THE STEAM ENGINE INDICATOK. 

A is a case or jacket enclosing a cylinder, 
into which a piston is nicely fitted to move 
Avithout friction ; to the upper side of this piston 
is attached a steel helical spring, the upper 
end of which is fastened to the cap or head 
of the cylinder ; to the upper end of the piston- 
rod B is directly jointed the short lever C 
D, whose short end is jointed to the head of 
a vibrating standard at D, and its long end is 
jointed to the long lever E F at the point C. 
The long arm of the lever E F is jointed at its 
outer extremity to a second vibrating standard 
at E, and to the other extremity is attached 
the pencil F. To the case A is permanently 
attached the horizontal plate G, at one end 
of which is jointed a corresponding plate H, 
situated above the former and carrying the 
revolving drum, covered by the paper cylinder 
I. To this drum is attached a cord, wound 
around a groove at its base and carried by the 
guide wheel K, between the two extra guide 
wheels L and M ; the guide wheels L and M 
are attached to the arm N, which swivels around 
a point in line with the axis of guide wheel 
K, and is held in its proper position by the 
thumb-nut O. The drum carrying the paper 
cylinder I is rotated in one direction by the 



THE STEAM ENGINE INDICATOR. 11 

tension on the cord, and in the reverse direction 
by the reaction of a spring enclosed therein ; the 
tension upon this spring may be adjusted to suit 
by the thumb-nut at the open end of the drum. 
The plate H, carrying the drum and paper 
cylinder, is held away from the pencil F by a 
spring situated between the plates H and G, 
directly in line with the axis of the drum, until 
the operator desires to take a diagram. By 
pressing upon the handle P the paper cylinder 
is moved forward and the pencil comes in 
contact with the paper. Immediately upon 
removing this pressure the paper cylinder 
automatically assumes its former position. 
Two adjustable stops determine the amount of 
this motion and regulate the force with which 
the pencil presses upon the paper, a hair line 
beins^ attainable without friction. The bushino- 
which carries the pencil is bored to receive a 
graphite or metallic wire, and is supplied with 
means for holding it in any position desired. 
The piston-rod is bored at each end almost 
half its length, leaving a thin partition or 
stop in the centre ; the upper chamber is used 
as a reservoir for a lubricant, and is provided 
with pin-holes close to the partition to allow the 
oil to flow out and down, and so lubricate the 



12 THE STEAM ENGIJSE INDICATOK. 

rod and piston ; the lower chamber allows the 
^team to enter and warm the lubricant, causing 
it to assume a more limpid form and flow freely 
in cold weather. The piston-rod is thus made 
lighter without weakening it materially. A 
minute portion of felt placed at the bottom of 
the reservoir will prevent the oil frora flowing 
too readily. It can be filled at the cross-head 
with a few drops of oil, by using a common 
pressure-oiler with a very small nozzle. To 
adjust the pencil to the proper position for 
springs of diff'erent scales, the head of the piston- 
rod is provided with a screw-threaded sleeve 
and lock-nut, by means of which the pencil may 
be made to assume any desired height. If it is 
washed, the guide wheels, etc., may be removed 
to the opposite end of the plates H and G. 
The use of a revolving drum for transmitting 
motion to the paper having been demonstrated 
to be the best means for the purpose, it has been 
adopted ; the only prerequisites being sufficient 
strength of spring and inelasticity of cord to 
overcome the momentum of the reciprocating 
parts. In any other devices, such as require a 
connecting-rod, there is imparted to the latter a 
tremulous and excessive motion, caused by its 
length and weight running at high speed when 



THE STEAM ENGINE INDICATOR. 15 

connected with a vibrating arm, which is trans- 
mitted to the lines of the diagram, thus pro- 
ducino; error. 

The greatest degree of accuracy and excel- 
lence is maintained in the manufacture of this in- 
strument, and if properly connected and operated 
its indications may be relied upon implicitly. 

The advantao^es in usino- this Indicator are 
numerous, and a few of the most obvious need 
only be mentioned. 

First, The motion of the pencil is a uniform 
multiplication of the piston motion. 

Second. The parallel motion is a true par- 
allel and not a geometrical approximation. 

Third. The weight of the reciprocating 
parts is greatly reduced. 

Fourth, The parts which require the most 
lubricating, viz., the cylinder, piston and rod, 
are automatically oiled. 

Fifth. The pencil instead of projecting be- 
3^ond the piston-rod several inches is directly 
behind the piston-rod, only about one quarter 
of an inch. 

Sixth, It is more easily operated. With 
former Indicators it was necessary to be an 
expert (to some extent), with a delicate sense 
of touch, to determine just the proper force tcK 



14 THE STEAM ENGINE INDICATOR. 

move the pencil against the paper, so not to 
tear it or cause undue friction. Now in this 
Indicator all this is predetermined, and is so 
nicely adjusted that a child can operate two 
Indicators — one on each end of the engine 
cylinder — simultaneousl}^ without the slight- 
est difficulty, and obtain hair lines without 
friction. 

Seventh, This instrument can he used right 
or left handed, by simply removing the guide- 
wheels, etc., to the opposite end of the 
plates. 

To adapt the Indicator to any pressure, 
springs are made of the following scales : 



N'os.— 8 12 16 20 24 30 40 50 60 80 100 
Lbs.— 24 36 48 60 70 90 120 150 180 240 300 



The number of the spring represents the 
pounds per square inch required to compress 
it sufficiently to move the pencil vertically one 
inch on the diagram. The figures in the lower 
line designate the maximum pressure of steam 
or steam and vacuum, w^hich, together with 
space allowed at each end of stroke for adjust- 
ment, equals the whole distance which the pen- 
cil can travel. 



THE STEAM EXGIXE IXDICATOR. 15 

WHAT CAN BE ASCERTAINED BY THE 
USE OF THIS INDICATOR. 

First. Whether the steam passages from the 
boiler to the cylinder are of sufficient size to 
supply steam in time to produce the best re- 
sults ; and what proportion of the boiler pres- 
sure is utilized. 

Second. Whether the discharge passages 
from the cylinder are of sufficient size to relieve 
properlj^ ; and, if not, how much remains as 
counter-pressure . 

Tliivd. Whether the piston is properly 
fitted ; or allows steam to escape into the 
.exhaust. 

Fourth. What pressure of steam there is 
on the piston at every position in the cylinder ; 
as well as its averao:e. 

Fifth. At what point in the stroke, and at 
what pressure the steam is cut oflf ; and whether 
it is cut oft' sharply or is wire-drawn. 

Sixth. At what pressure the steam is finally 
released. 

Seventh. How soon in the stroke the high- 
est pressure is reached : and how well main- 
tained. 



16 THE STEAM ENGINE INDICATOR. 

EigMli, The amount of vacuum acting upon 
the piston of a condensing engine at every point 
in the stroke ; and its average. 

Ninth. Whether there is any compression 
of the steam remaining in the cylinder before 
the stroke commences ; and, if so, where it be- 
gins and how high it rises. 

Tenth, The actual consumption of steam 
in giving motion to the engine alone ; and 
also what additional steam is used in giving 
motion to the shafting or the machinery at- 
tached. 

Eleventh. Where power is sold, how much 
each tenant consumes ; and in large establish- 
ments, where friction of shafting and machinery 
forms a large proportion of the resistance 
oflered, it guides in the selection of proper 
lubricants. 

Tivelfth. The economy of using high pres- 
sure steam and expansion; and the relative 
efficiency of the different apparatus for procur- 
ing expansion. 

Thirteenth. The quantity of water that 
would under given circumstances be most 
economically used in the condensation of the 
steam, if attached to the air-pump of condens- 
ing engines. 



THE STEAM ENGINE INDICATOR. 17 

Fourteenth, The accuracy of the steam gage 
when applied correspondingly. 

Fifteenth. Whether the valves are properly 
adjusted and in good condition or not. 



DIRECTIONS FOR USING THE CROSBY 
INDICATOR. 

Hoio to Attach it, — The Indicator should be 
connected as closely to the cylinder of the 
engine as possible, as pressure is lost by the 
use of pipes. The connection may be made 
by drilling the cylinder or its heads ; but care 
should be used in drilling the cylinder that 
the piston does not cover the hole when at 
the end of the stroke. By allowing a small 
quantity of steam to enter the cylinder as 
the drill begins to go through, all chips will 
be blown out. Xo lead or putty should be 
used in making the connections. Keep clear 
of the thoroughfares, as steam passing the 
hole for the connection reduces the pressiu^e 
in the Indicator; screw the stop-cock to its 
place, then open it and blow steam through 
to clear the connections, and attach the In- 



18 THE STEAM ENGINE INDICATOR. 

dicator by means of the union nut, when in 
the best position to operate ; move the ad- 
justable guide wheels to the best position for 
receiving the cord, and then connect the cord 
to the apparatus for transmitting the motion 
from the engine to the paper. The cord must 
be connected with some part of the engine 
having a movement co-incident with the piston, 
and which would give the paper cylinder a 
movement of about three-fourths of a revolu- 
tion ; it will frequently be found necessary to 
erect a temporary rocker-shaft, or lever con- 
necting with the cross-head, for reducing the 
motion ; for a beam-engine, a point on the 
parallel bar, beam, or beam-centre will answer. 
Beyond these suggestions, the ingenuity and 
judgment of the operator must determine what 
is required to produce the proper movement. 
Care should be taken that the cord be so 
led off from the part which gives it motion 
that when the engine is on half-stroke it will 
be at right angles to such part ; but between 
the first pulley and the Indicator it may take 
any required direction. Use as few pulleys 
and as short a cord as possible. It is also 
necessary that the length of the cord be easily 
adjusted and readily connected and discon- 



THE STEAM ENGINE INDICATOR. 19 

nected. To meet these requirements, one end 
should be provided with a running loop and 
hook (see cut No. 3) . Arrange the motion of the 




No. 3. 

paper cylinder, hv means of the running loop, 
so that it shall not be checked at one end of 
the stroke by the stop fixture, and thereby 
slacken the cord ; nor at the other end by the 
springs for holding the paper on the cylinder, 
coming in contact with the pencil ; either of 
which would render the diagram useless. 

HoiD to take a Diagram. — Remove the paper 
cylinder from the drum and place the paper 
upon it ; the easiest method of doing this is to 
secure the two lower corners of the paper be- 
tween the thumb and finger, then put the loop 
so made over the top of the cylinder ; slip the 
edges under the springs and slide the whole 
down to the bottom, leaving it smooth and 
tight. 

Instead of the ordinary springs for holding 
the paper upon the cylinder, a hinged snap- 
lever supplied with pins and corresponding pin 



20 THE STEAM ENGINE INDICATOR. 

holes, can be furnished when desired. (See 
Appendix.) This facilitates the placing of 
the paper upon the cylinder, and keeps it 
perfectly tight and smooth. 

Eeturn the cjdinder to the drum ; adjust 
the cylinder to the pencil for a hair line ; open 
the stop-cock and allow the steam to enter, 
heat and expand the cylinder to give freedom 
of motion, then turn the T handle of the cock- 
plug to a horizontal position to allow of 
atmospheric pressure under the piston as well 
as above it ; connect the cord and draw the 
atmospheric line ; then turn the T handle to a 
vertical position and press the paper cylinder 
up to the pencil, by means of the handle P, 
long enough for the engine to make one revolu- 
tion. No nicety is required in this, as the 
adjustable stop determines the distance moved 
and delicacy of the lines drawn. The engine 
should be allowed to run a short time before 
taking diagrams, to clear the cylinder from 
water and thoroughly heat it. 

If it is a new Indicator allow its piston to 
work for a few moments before taking a 
diagram. After a diagram is taken, disconnect 
the cord by means of the hook and close the 
stop-cock, as continual working only wears out 



THE STEAM ENGINE INDICATOR. 21 

the instrument needlessly. Remove the paper 
and make the proper memoranda upon the back 
at once; this should at least include the follow- 
ing particulars, viz., description of engine; 
scale or spring ; diameter of cylinder and piston- 
rod ; which end of cylinder ; length of stroke ; 
number ofrevolutions per minute ; cubic contents 
of clearance and thoroughfares ; pressure of 
steam in the boiler ; and, if a condensing engine, 
the vacuum indicated by the gage. As many 
more particulars and circumstances should be 
added as can be readily ascertained ; among 
which it is well to include the length of con- 
necting-rod and the weight of all the recipro- 
cating parts. 

To avoid mistakes, designate the two ends 
of the cvlinder as out-end and craiik-end, 

Hoiv to take apart and clean it. — Immedi- 
ately after using the Indicator it should be 
properly cleaned and oiled. This is done b}^ 
disconnecting the short lever at the points B 
and C ; then unscrew the cap or head of the 
cylinder and carefully remove the piston and 
spring ; empty the cylinder of water and clean 
and dry all the parts ; lubricate the cylinder, 
joints and journals, with a very small quantity 
of oil, which must be free from all impurities — 



22 THE STEAM ENGINE INDICATOR. 

porpoise or watch oil is the best ; never unscrew 
the rod from the piston. If the inner surface 
of the cylinder or the piston should get 
scratched by any means (and it will be detected 
by the unsteady lines of the diagram) it should 
be remedied at once, and in this manner : When 
the instrument is apart, cleaned and oiled, the 
piston may be replaced in the cylinder without 
the spring ; screw on the cap or cylinder-head 
for a guide and then revolve the piston-rod 
between the thumb and finger, at the same time 
moving it up and down ; remove it occasionally 
and wipe all the parts clean ; after a few opera- 
tions the surfaces will wear themselves smooth. 
No grinding or polishing should ever be resorted 
to. When the parts are clean and the cylinder 
plumb, the piston, with spring removed, should 
move freely and uniformly, but slowly, through 
the whole length of the stroke, with the levers 
attached and the cock closed ; with the cock 
open it should drop freely from any position. 
In putting the parts together the levers and 
standards should be tested to see if they move 
freely of their own weight and without side 
motion in the joints ; then securely screw the 
spring to the piston and cap. Care should be 
taken that the slot in the head of the piston- 



THE STEAM ENGINE INDICATOR. 23 

rod is in line with the lever when making con- 
nection, otherwise it would bind and cause 
friction. ^ 

DIAGRAMS. 

It must always be remembered that the Indi- 
cator's oflSce is only to represent the pressure 
on the piston at each point of the stroke, by 
lines circumscribed upon paper. The correct 
reading of these lines is left entirely to the 
operator. For the mere purpose of ascertain- 
ing the condition of the valves, piston, etc., it 
will be quite sufficient to scan the outlines of 
the diagram; but if the power of the engine is 
required, the mean pressures upon the opposite 
sides of the piston must be ascertained by meas- 
urement. In using a graphite wire for marking 
the lines, any paper susceptible of taking a 
line impression from an ordinary lead pencil 
will answer, but if the metallic point is used, a 
paper expressly prepared for the purpose is 
necessary, and will be furnished upon applica- 
tion. The impression in this instance is indelil)le. 

Diagrams should be taken from both ends of 
the cylinder, and simultaneously, if practicable ; 
and the mean result of the two taken as a basis 
for estimating the power of the engine. 

The common idea that if the valves are 



24 THE STEAM ENGINE INDICATOR. 

properly adjusted, two diagrams thus taken 
must be alike, is a mistake. They will in 
some respects be dissin^lar, from various 
causes, one of wiiich is the difference in the 
speed of the piston at opposite ends of the 
stroke. (See Diag. 9.) There may be a differ- 
ence also in the size of the thoroughfares. The 
extreme ends of the diagram are produced at 
the exact time the engine is passing its centres. 
In diagrams of non-condensing engines, the 
lower line is usually drawn slightly above the 
atmospheric pressure (see Diag. 1) ; while in 
condensing engines it approximates more or less 
to that of perfect vacuum (see Diags. 8 and 9) . 

EXPLANATION OF LINES OF DIAGRAMS. 

For convenience in describino^ diao;rams their 
several parts will be described as follows : 

Atmospheric Line, AA. 

Clearance Ijine, AB. 

Boiler Pressure Line, BP. 

Admission Line, , . HC. 

Steam Line, CD. 

Point of Cut-off, D. 

Expansion Curve, DE. 

Point of Exhaust, E. 

Exhaust Line EF. 

Counter Piessu.re Line, EG. 

Compression Curve, GH. 

Vacuum J.ine YY. 

Theoretic Curve, . . . . . Dotted Line. 

(See Diag. 1.) 



THE STEAM ENGINE INDICATOR. 25 

In condensino' eno-ines consider line EFG 
as all exhaust. 

Different eno-ines oive different diao-rams, 
and diaoTams taken from the same eno-ine under 
different circumstances differ. On account of 
the diversity of style of engines, and the attend- 
ing variety of circumstances and surroundings, 
no design for a perfect diagram will answer for 
more than one particular engine,' and then only 
with one particular combination of conditions, 
as every change, whether of speed, pressure, 
friction, work, etc., produces different results. 
The important thing always is to procure the 
greatest mean effective pressure with the lowest 
terminal pressure. But a few general rules may 
apply. By taking the different lines drawn bj^ 
the Indicator, in succession, commencing with 
the stroke, Ihe main features of merit or defect 
may be pointed out. For convenience to the 
beginner, however, all the lines of the Diagram 
will be noticed and explained in the usual order 
of production. 

The A.t7nosj}]ieric Line is traced wlien the 
atmosphere has free access to both sides of the 
piston of the Indicator before steam is admitted, 
and indicates the line of atmospheric pressure, 
or zero, on the steam gage. The following 



26 THE STEAM EXGINE I^^DICATOR. 

lines are automatically traced by the Indicator 
and are described as follows : 

The Admission Line represents the rise of 
pressure due to the admission of steam to 
the cylinder. If it is at right angles to the 
atmospheric line, and is not curved or inclined 
forwards where conjoining with the steam line, 
it indicates that full pressure is exerted upon 
the piston at the commencement of the stroke, 
caused either by the quick entrance of steam, or 
by compression, or by both combined. Should 
this line incline forwards and form a curve in 
connecting with the steam line, the reverse is 
indicated ; or should this line continue ver- 
tically beyond, and then suddenly drop to the 
level of the steam line, it signifies that the 
steam is wire-drawn and cannot enter the 
cylinder with freedom sufficient to keep up the 
full pressure as the piston starts forward ; but 
should this line, after projecting above, be 
suddenly depressed below the level of the 
steam line, vibrating back and forth one or 
more times on the latter line with acute angles 
of return, it may be attributed to the momen- 
tum of the reciprocating parts of the Indi- 
cator while running at very high speed. (See 
Diag. 7.) 



THE STEAM ENGINE INDICATOR. 27 

The Steam Line represents the pressure of 
the steam upon the piston and its duration^ 
while acting directly, that is, being constantly- 
reinforced, from the boiler ; and shows what 
proportion of boiler pressure is attained, and 
how soon, and how well maintained. Should 
this line dip below a horizontal (see Diag. 5) 
it is an indication of either wire-drawing of the 
steam somewhere between the boiler and the 
cylinder, or loss of steam from some cause ^ 
such as leakage around the piston, or conden- 
sation of steam on entering the cylinder from 
loss of heat by radiation and condensation, in- 
ternal and external. It also shows at its ter- 
mination the point at which the valve closes or 
steam is cut off. 

The TJxioansion Line commences at the point 
of cut-off wdiere the steam line ends, and rep- 
resents the fall of the pressure due to the 
expansion of steam remaining in the cylinder 
after cut-off. The nearer this line corresponds 
to the theoretic expansion curve the better, but 
it generally runs somewhat above, as the pis- 
ton continues on its course. This is caused 
partly by leakage of the valve. Should this 
line, after falling considerably, begin to rise 
again, and show before the termination of the 



28 THE STEAM ENGINE INDICATOR. 

stroke a pressure in excess of what it did at 
some preceding point, it indicates that re- 
^yaporation of the moist steam has taken place. 
The heat for this purpose is supplied by the 
surfaces of the cylinder and piston in contact 
with the steam, and must he regained at the 
lieo'innino' of the next stroke from the direct 
steam. The excess or rise of the line measures 
the heat lost in the process. Where the ex- 
jDansion curye intersects the steam line, there 
is the point of cut-off; it is clearly defined 
where the yalye closes quickly (see Diag. 4), 
but where it closes slowly it is more difficult 
to locate ; in the latter case, take the point on 
the curyature where it chanoes from conyex to 
concaye, and through it extend the expansion 
<3urye upwards by the eye until it cuts the 
steam line ; the point of intersection is the 
apparent cut-off. (See Diag. 1.) Should the 
expansion line drop below the true curye, it 
indicates, in a non-condensing engine, that the 
piston leaks, or that condensation has taken 
place ; in a condensing engine, that either the 
piston or the exhaust yalye leaks. Should 
this line fall below the atmospheric line 
(see Diag. 3), the area thus enclosed should 
be measured and deducted from the impelling 



THE STEAM ENGINE IXDICATOR. 29 

pressure, as it represents counter-pressure or 
power lost. 

The steam may be cut off so early that ex- 
pansion cannot be advantageously employed 
even with the highest pressure. If this line is 
loavy^ consequent upon extreme speed andpres- 
sure and the use of a spring worked at its^ 
utmost capacity, or should the pencil describe 
several diaoTams before removal, the averaa^e 
or mean should be ascertained. 

The Exhaust Line commences where the ex- 
pansion line ends, and is traced while the excess 
of pressure remaining at the point of exhaust is 
being released. It indicates whether the ex-^ 
haust valve opens properly or not, and whether 
the exhaust port and passages are of sufficient 
size for the free exit of the steam. 

27^6 Line of Counter-pressure in a non-con- 
densing engine represents by its distance above 
the atmospheric line the pressure in front of the 
piston during the return stroke. (See Diag. 
1.) Its presence, to any considerable degree, 
indicates one or more defects, such as smallness^ 
of exhaust port or pipes, leakage of piston 
or valves, etc. In a condensing engine it 
indicates by its distance below the atmospheric 
line the amount of vacuum existing under the 



30 THE STEAM ENGINE INDICATOR. 

piston at eveiy point of the return stroke, 
lio^v quickly produced, and how well main- 
tained ; the efficiency of the condenser, air pump 
and exhaust valye. (See Diags. 8 and 9.) 

The Comjpression Line^ when it exists, rep- 
resents the rise of pressure due to the compres- 
sion of the steam shut in the cylinder by closure 
of the exhaust, and indicates the point on the 
return stroke at which the exhaust-valve closed 
and compression commenced, and the amount 
of pressure resisting the movement of the piston 
as it nears the end of the stroke. (See Diags. 
1, 4 and 6.) This pressure is called "cushion- 
ing," and should be calculated and deducted 
from the impelling pressure. Should this line 
be projected above the boiler-pressure, then sud- 
denl}^ drop in nearly a perpendicular line to the 
level of the steam line, thus forming a loop, it 
indicates an excess of "compression, due to 
closing the exhaust too soon. 

The remaining lines are drawn by the oper- 
ator, and are described as follows : 

Boiler Pressure Line is drawn when the 
engine is blocked so that the full pressure on 
the boiler can act upon the Indicator, thereby 
testing the steam gage, or it may be drawn by 
scale, at a distance from the atmospheric line 



THE STEAM EXGIXE INDICATOR. 31 

equal to the pounds pressure per square inch 
as shown by the steam o*ao'e, if this is known 
to be correct. This line shows by comparison 
with the steam line the amount of pressure in 
boiler not utilized by the engine. 

The Vacuum Line is laid down by scale, 
usually 15. pounds below the atmospheric 
line, but 14.7' is nearer correct, and rep- 
resents perfect yacuum or absence of all 
pressure. 

The Clearance Line is laid ojff a certain dis- 
tance from the steam end of the diaoram, which 
distance is to the whole leno*th of the diaOTam 
as the total yolume of clearance, including ports, 
is to the piston displacement. It represents the 
waste room between the cut-off yalye and 
piston when the latter is at this end of the 
stroke, and is found by either calculating or 
actually measuring' by water the cubic inches 
contained in the space between the piston and 
coyer when the eno-ine is on its centre, and 
that of the ports and passage ways back to 
the yalye ; diyide by this the solid contents 
of that portion of the cylinder occupied by 
the stroke of piston, and the quotient will 
represent the denominator of a fraction, which 
with one for a numerator will giye the pro- 



32 .THE STEAM ENGINE INDICATOR. 

portional part of the length of the diagram 
to be added to the steam end thereof. (See Fig. 
1 . ) Through the point thus formed draw a line 
at right angles to the atmospheric line. When 
the clearance is taken into account, this space 
must be reckoned as part of the diagram in cal- 
culating the average pressure, and in producing 
the theoretic curve, or line of perfect expansion. 

The Theoretic Curve represents the line of 
true expansion, or isothermal line, and shows 
by comparison with the line of expansion drawn 
by the Indicator the degree of excellence at- 
tained in regard to the construction, adjustment 
and working of valves, fitting of piston, pro- 
tection of the cylinder and efficiency of appa- 
ratus for procuring expansion. 

According to the law of expansion, if a perfect 
gas enters freely to tlie cylinder while the pis- 
ton is travelling a distance equal to one of the 
above divisions (see Diag. 2) , and is then cut off 
and the piston continues onto the next division, 
supposing the gas to remain at the same tem- 
perature, the pressure is reduced one-half; con- 
tinue the piston to the third and it will be 
reduced to one-third ; if to the fourth^ to one- 
fourth ; and so on to the end of the stroke. 

This line should always be drawn after the 



THE STEAM ENGINE INDICATOR. 33 

diagram is taken, so that the expansion line 
actually produced may be compared therewith. 
If the valves are properly constructed and ad- 
justed, the piston properly fitted, and the 
cylinder sufficiently protected, or jacketed, 
these two curves should nearly coincide, the 
nearer the better. The true curve commences 
on the steam line at the point of cut-off, and 
terminates at the end of the stroke. It may be 
ascertained in the following manner : 

Let an area be supposed (seeDiag, 2) whose 
length represents the stroke of the engine and 
clearance, and whose breadth represents ninety 
pounds of steam pressure above the atmosphere, 
scale forty pounds to the inch. Draw the line 
of perfect vacuum W ; divide the whole area 
into any number of equal divisions, by drawing 
lines (ordinates) at right angles to the vacuum 
line, and have one of these lines pass through 
the point of cut-off; numl)er these lines in the 
direction of stroke, 1, 2, 3, 4, etc. Take the 
number of the line at the point of cut-off for 
a numerator and the number of the next line 
for a denominator, and this fraction will, by 
measuring from the vacuum line, determine 
the point on this next line, through which 
the theoretic curve passes. Continue in this 



34 THE STEAM ENGINE INDICATOR. 

way through the whole number of lines ; 
then connect these points by lines drawn suffi- 
ciently curved to make the whole curve regular. 
The result is the theoretic curve. The ^freater 
number of divisions the more perfect the curve 
will be ; but ten is generally sufficient for ordi- 
nary purposes. Should difficulty occur in 
ascertaining a distance which will enter into 
both divisions without a remainder, divide the 
steam line from clearance to the point of cut- 
off, into equal spaces ; then continue with these 
spaces through the remaining division, even 
should they project beyond the diagram, as 
the terminal pressure can be measured where 
the curve crosses the line desiofnatino- the ter- 
mination of the diaoram. 



TO COMPUTE THE AVERAGE 
PRESSURES. 

Divide the diagram into a number of equal 
spaces by lines drawn at right angles to the 
atmospheric line ; ten is usually sufficient, but 
twenty is l>etter if great accuracy is required. 
(We furnish, when requested, a convenient 
instrument for this purpose, i.e., a propor- 



THE STEAM ENGINE INDICATOR. 35 

tional divider, which with a small tiy-square 
answers every purpose.) 

In non-condensing engines^ when calculating 
the average pressure on the steam side of the 
piston for the whole stroke, the mean pressure 
in each division or space enclosed by these lines, 
between the upper line (steam and expansion) 
and the atmospheric line, should be first ascer- 
tained. This may be done either by carefully 
measuring each space between the atmospheric 
line and the upper line of the diagram, by tl/e 
scale corresponding to the spring used in the 
instrument, and the sum of these measurements 
divided by the number of spaces gives the aver- 
age pressure per square inch upon the work- 
ing side of the piston, or average impelling 
pressure for the whole stroke ; or upon meas- 
uring the spaces with a common ride, divide 
their sum by the number of spaces, and 
multiply the quotient l)y the number of the 
spring, and the result is the same. Proceed 
in like manner to find the average resisting 
pressure upon the opposite side of the piston, 
measuring the distance in each space l)etween 
the lower line (counter-pressure and compres- 
sion) and the atmospheric line ; the difference 
between the average impelling pressure and the 



36 THE STEAM ENGINE INDICATOK. 

average resisting pressure gives the mean effect- 
ive pressure exerted. (See examples.) Shovild 
the expansion line fall below the atmospheric 
line, the area of the loop thus formed should 
be measured in like manner, and deducted the 
same as the compression and counter-pressure. 
If the diagram is also divided by lines drawn 
parallel to the atmospheric line, into equal 
spaces and corresponding to a certain number 
of pounds pressure, say five pounds, as per 
scale, beginning at vacuum, the operator is 
enabled readily to read the general charac- 
teristics by sight. A very simple method 
of measurinof diaorams has been suo'o-ested 
which is much easier than either of the above, 
and reduces liability of error. Take a nar- 
row strip of paper which has a straight 
edge, place it across the diagram, and let 
one end of this strip come directly over the 
atmospheric line ; then with a knife blade or 
sharp pencil mark the length of the first space 
as determined by the steam line ; then move the 
paper along to the next space, placing the mark 
made by the pencil over the atmospheric line ; 
then make another mark at the point where it 
crosses the steam or expansion line, whichever 
it may be, being careful always to take a point 



THE STEAM ENGINE INDICATOR. 37 

on the upper line, which shall represent the 
mean length as nearly as possible ; so proceed 
until the length of each space has been added 
to the first ; then measure with a rule from the 
end of the paper to the last pencil mark, divide 
this by the number of spaces to get the average 
length, and multiply the quotient by the number 
of the spring in use, and the result is the aver- 
age impelling pressure per square inch. Pro- 
ceed in like manner to measure the average 
resisting pressure, etc. Ten is the usual 
number of spaces used, but for exactness 
tT\^enty is better. 

In condensing engines it is usual to find the 
value of the steam and vacuum pressures 
separately. To do this, measure from the 
atmospheric line upiuards for steam, as be- 
fore, and downwards to the exhaust line 
for vacuum. In calculating the average pres- 
sures of each, proceed in the same manner 
described for non-condensing engines, not 
forgetting the remark concerning the de- 
duction necessary should the expansion line 
drop below the atmospheric line before the 
completion of the stroke. The sum of these 
average pressures is the mean effective pres- 



38 THE STEAM ENGINE INDICATOR. 

sure exerted. Draw the line of perfect vacuum 
at the bottom, measuring hy scale from the 
atmospheric line ; for greater accuracy and 
to ascertain the duty performed by the condenser 
and air-pump this should be determined by the 
barometer, as the pressure of the atmosphere 
varies according to its density. 

In lieu of measuring Diagrams from the 
atmospheric line, as a base, some prefer to 
use the vacuum line, representing, as it does, 
the line oi no pressure ; in which case any loop 
formed by the expansion line dropping below 
the atmospheric line will necessarily have 
been included in the resisting pressure, and 
deducted the same as compression and counter- 
pressure. 

A quicker method of ascertaining the effect- 
ive pressure^ whether in condensing or non- 
condensing engines, is to measure the spaces 
between the upper and lower lines of the dia- 
gram without regard to the atmospheric line, 
and then proceed in the manner as before stated. 
(See examples.) This does away with separ- 
ate measurements, excepting when a loop is 
formed in non-condensino' enoines. 



THE STEA31 ENGINE INDICATOR. 39 

THE POWER OF THE ENGINE. 

It is customary to designate the capacity of an 
engine in "horse-powers" as the units of meas- 
urement, by which term is understood, power 
sufficient to raise 33,000 pounds one foot high 
per minute. Its distinctions are "nominal," 
" actual " and " effective " horse-power. The 
first is applied to the size, the second to the 
power of the steam engine, and the last to the 
power, less the force, which is required to 
overcome its own friction, running at the same 
speed. The friction of the engine alone the 
Indicator will show by taking a separate dia- 
gram. (See Diag. 3.) But the increase of fric- 
tion when resistance is being overcome is not 
known to any degree of certainty, excepting 
the fact that it increases as the resistance 
increases, and is proportionately less as the size 
of the engine is increased ; and it is generally 
estimated at five per cent, of the actual power 
exerted. The actual power is found correctly 
only by the use of the Indicator, and the eftective 
power by deducting from the actual power the 
power required to overcome the friction of the 
engine alone, together with five per cent, of the 
actual power for additional friction, created by 



40 THE STEAM ENGINE INDICATOR. 

the increased resistance when loaded. (See 
Examples.) 

Initial pressure is the pressure which acts 
upon the piston at the beginning of the stroke. 

Terminal pressure applies to exhaust or re- 
lease pressure that would exist at the end of 
the stroke, if the steam had not been released 
earlier. 

TO CALCULATE THE POWER OF EN- 
GINES. 

The mean eflective pressure, multiplied by 
the number of square inches contained in the 
piston, and this product multiplied by the mean 
velocity of the piston in feet per minute, and 
the result divided by 33,000, gives the actual 
horse-powers exerted. Another method of cal- 
culation which commends itself is to multiply 
the area of the piston in inches by the speed of 
the piston in feet j^er minute ; divide the pro- 
duct by 33,000, and the quotient will be the 
number of horse-powers exerted for each pound 
of eflFective pressure on the piston ; this multiplied 
by the average eflective pressure per square 
inch gives the actual horse-powers of the engine. 

To obtain the effective power ^ as has been 
before said, the power required to run the engine 
alone, ascertained by the Indicator, must be 



THE STEAM ENGINE INDICATOR. 41 

deducted from the actual power, together with 
five per cent, of the latter for increased friction 
when overcoming resistance occasioned by the 
load. (See Examples.) 

To ascertain the precise area of the piston 
that is acted upon by pressure, the cross-sec- 
tional area of piston-rod should be deducted 
from the side to which it is attached or one- 
half from the mean. 

Ordinarily an eno-ine will o-ive the same dia- 
gram at each successive revolution, unless the 
resistance should vary, but should several lines 
be drawn their mean should be taken as the 
proper diagram. In ascertaining the power 
requisite to o^'^rcome different resistances, it is 
better that the speed of the engine should 
be the same in each case. 

If the Indicator is used on a locomotive, the 
grade, curve, weight of train and diameter of 
the driving-wheels should be taken into account 
in certain calculations. 



TO MEASURE THE QUANTITY OF STEAM 
CONSUMED IN THE CYLINDER. 

Add to the diagram the clearance ; multiply 
the pressure in the cylinder (measuring from 



42 THE STEAM ENGINE INDICATOR. 

the line of perfect vacuum) at the point in the 
stroke where the steam is released, by the 
area of the piston in square inches, and 
the product by that part of the length of 
s.troke, measured in inches, from the clear- 
ance line to the point of release. Multiply 
this result by the number of strokes per hour ; 
reduce the cubic inches to cubic feet. Multiply 
this by the weight of a cubic foot of steam at 
the pressure at release ; from which subtract the 
quantity of steam shut in by compression, ascer- 
tained in like manner, for the pressure and part 
of stroke, and the difference will be the pounds 
of water used per hour, passing through the 
cylinder in the shape of working steam. 

While the Indicator Diagram, taken as an ex- 
ponent of the steam engine, furnishes facts which 
could not otherwise be ascertained, among 
others, the amount of steam consumed in the 
cylinder as working material, it does not indicate 
the amount actually furnished by the boiler. 
This is only ascertained by actual measurement 
of water evaporated, and is in excess ; the 
difference measures the loss from leakage, prim- 
ing, blow-off, radiation and conduction and en- 
trained water (of which priming is an extreme 
degree), and cannot be debited to the engine. 



EXAMPLES 



Compute the Mean Effective Pressure, Actual and 
Eff^ective Horse-powers, from Dlagravis Nos, 3 and 4. 

MEASUBED BY SCALE IN POUNDS. 

From the sura of impelling pressures in spaces, 290 lbs. 
Deduct the sum of resisting pressures in spaces, 10 '' 

Divide the remainder by number of spaces, 10)280 

Result, mean effective pressure, 28 

OR, MEASURED BY RUUE IX INCHES. 

From the sum of distances from atmospheric line 
to upper lines, 7.25 

Deduct the sum of distances from atmospheric line 

to lower lines, .25 

Divide the remainder by number of spaces, 10)7.00 

Multiply the quotient, .7 

By the number of spring, 40 

Result, mean effective pressure, 28 

OR, MEASURED WITHOUT REGARD TO ATMOSPHERIC LINE. 

In pounds per scale, = 280 -^ 10 = 28 = mean effective 
pressure. 

In inches by rule = 7 -r- 10 = .7 X 40 = 28 = mean effect- 
ive pressure. 

Multiply the mean effective pressure in lbs., 2S 

By area of piston in inches, 50.26 

Multiply this product, 1407.2S 

By the speed of the piston in feet per minute, oGO 

Divide this result by 33000 )506620.80 

The quotient is the actual horse-powers exerted, 15.352 

Or, multiply area of piston in inches, 50.26 

By speed of piston in feet per minute, 360 

Divide the product by 33000) 18093.60 

Which gives the horse-powers exerted per each 

lb. mean effective pressure, .548^^ 

Multiply this by the mean effective pressure, 28 

For the actual Horse-powers exerted, 15.3524 

From which deduct the power required to 

run engine alone, .24 

And 5% for increased friction when loaded, .76 1 

Result effective horse-powers of engine, 14.3524 



44 EXAMPLES. 

Cornpute the Mean Effective Pressure, Actual and 
Effective Horse-powers, from Diagram No. 8. 

MEASURED BY SCALE IN POUNDS. 

To the sum of pressures above atmospheric line, 84 lbs. 

Add the sum of pressures below atmospheric line, 120 " 

Divide this sum by the number of spaces, 10)204 '^ 



The result is the mean effective pressure, 20.4 ^' 

OE, MEASURED BY RULE IN INCHES. 

To the sum of distances from atmospheric line to 

upper lines, 7 inches 

Add the sum of distances from atmospheric line 

to lower lines, JjO ^' 

Divide this sum by the number of spaces, 10)17 " 

Multiply the quotient, 1.7 '^ 

By the number of the spring, 12 '' 

The result is the mean effective pressure, 20.4 *' 

OR, MEASURED WITHOUT REGARD TO ATMOSPHERIC LINE. 

In pounds per scale = 204 -4- 10 = 20.4 = mean effective 

pressure. 
In inches by rule = 17 -^ 10 = 1.7 X 12 = 20.4 = mean 

effective pressure. 
JVIultiply the mean effective pressure in lbs,, 20.4 

By area of piston in inches, 7088.24 

Multiply this product, 144600.096 

By the speed of piston in feet per minute, 300 

Divide this result by 3300 0)4.3380028.8 

The quotient is the actual horse-powers exerted, 1314.546 

Or, multiply area of piston in inches, 7088.24 

By speed of piston in feet per minute, 300 

Divide product by 33000) 2126472 

"Which gives the horse-powers exerted per each 

lb. of mean effective pressure, 64.4385 

Multiply this by mean effective pressure, 20.4 

For the actual horse-powers exerted, 1314.5454 

From which deduct the power required to 

run engine alone, about H%, say 20.0 

And 5% for increased friction when loaded, 65.7 85.7 

Kesult, effective horse-powers of engine, 1228.8454 



THE STEAM ENGINE INDICATOK. 



45 



DIAGRAM No. 1. 




46 THE STEAM ENGINE INDICATOR. 



DIAGRAM No. 2, 



^ > 



^^^■■L 

■■■■1 





< > 



THE STEAM ENGINE INDICATOR, 



47 



DIAGRAM No. 3. 




48 



THE STEAM ENGINE INDICATOR, 



DIAGRAM No. 4. 




THE STEAM ENGINE INDICATOR. 



4^ 



DIAGRAM No. 5 




50 



THE STEAM ENGINE INDICATOR. 



DIAGRAM No. 6. 




THE STEAM ENGINE INDICATOR. 



51 



DIAGRAM No. 7. 




52 THE STEAM ENGINE INDICATOR, 



DIAGRAM No. 8. 




Cylinder 95x120. 15 revolutions. 12 scale. Low Pressure 
Condensing. Crosby Indicator. 



THE STEAM ENGINE INDICATOK 
DIAGRAM No. 9. 



53 




CROSBY 

STEAM GAGE AND VALYE COMPANY. 

J. H. MiLLETT, President. Geo. H. Crosby, Superinteuueni, 
Geo. H. Eager, Treasurer. 



Sole Proprietors and Manufacturers of the 

iEtill 

Adjustable Pop Safety Valve, 
Steam Pressure Gage, 

Safety Water Gage, 

Automatic Reducing Valve, 

Steam Engine Inaicator. 

Sole Manufacturers and General Agents of 

THE "VICTORY" Steam Cylinder Lubricator, 

KEYES' SELF-TESTING PEESSUKE GAGE. 

Manufacturers of 

Steam Pressure and Vacuum Gages ^vith Bourdon Spring, 

Engine Revolution Counters, Marme Clocks, Hydraulic 

Gages, Test Gages, Test Pumps, Water Gages, 

Gage Cocks, Whistles, Pyrometers, Sah- 

nometers. Thermometers, etc., 

AND ALL INSTRUMENTS 

Incidental to the use of Sieana Engines and Boilers. 

DEALERS IN 

SCOTCH AND AMERICAN GLASS TUBES, 

And Steam Fittings of Every Description. 

COR. MILK AND BATTERYMARCH STS„ BOSTON, MASS. 

SEND FOR n.I.USTRATED CATALOGUE. 



56 



ArPENDIX 




Interior View. 

Bourdon Pressure and Vacuum Gages. 

This style of Gage is better adapted for indicating low 
pressures and vacuums than any other known, and is fully 
warranted for such uses. 

The pressure required should be stated in ordering gages. 

SIZES. 
No. 0, Brass Case and Ring, - - - 



1, 
2, 
3, 

I 

7. 

2y2, 

10, 



Iron Case, Brass Ring, 



Spun 



10 in 


. Dial 


- SVs 


(( 


6% 


tt 


- 6 


n 


bK 


it 


- 41^ 


ft 


3y> 


(t 


- 2V2 


tt 


^V2 


tt 


- C3/4 


tt 


(') 


(t 


- .^>y2 


tt 


4V2 


tt 



- r.i/o 



irass Ring, - - - "> '* 

Cases made with Deep Hkass Cases or Octago.n Fackd Rings 
when ordered. 

All Gages are graduated and tested by an open mercury column, 
and warranted cofect. 

m^^A Siphon is indispensable for every Steam Gage, and none war- 
ranted without it. 

SEND FOR ILLUSTRATED CATALOGUE. 



APPENDIX , 



57 




Interior VrEW. 

Crosby's Improved Steam Gages. 

The hollow spring in this Gage is so shaped and arranged, 
and the mechanism is such, that the vertical as well as the 
horizontal movement of its free ends is fully utilized. It 
thereby permits the use of springs 100 per cent, stronger 
than can be used in any other gage, so presenting its setting 
under any pressure which may he indicated upon its dial. 
While this Gage is especially adapted for high pressures, it 
is as sensitive as the Bourdon Gage. No vibration of the 
pointer. No Freezing. 
^ SIZES. 

No. 0, Brass Case and Ring, - - - - 

i« 2 «. « « 

f( 2* •* ** ** - - - - 

« ^^ it u " . , - - 

(( 5' « «< «<_.-- 

No. 1 V2, Iron Case, Brass Ring, - - - - 

u 21/2. '* " . - . - 

« 01/ it »< . - - . 

" 4: " ...--- 

u 51/ it *« _ _ - ^ *^^ 

Gages marked to any pressure not exceeding 500 lbs. per square inch. 

m^ A Siphon is indispensable for every Steam Gage— and none 
warranted without it. ■, ^s^a 

All Gages are graduated and tested by an open mercury column ana 
warranted correct. „. , „ o„„« 

A maximum pointer can be attached to any High-Pressure Gage. 
SEND FOR ILLUSTRATED CATALOGUE. 



10 in 

SV2 
6% 
6 

6 

51/2 



Dial. 

tt 

(( 
(( 
tt 
it 
ii 

a 

it 
n 



58 



APPENDIX. 



Crosby's Improved Hydraulic Gages. 

To sustain witli safety the enormous pressure to which 
these gages are subjected, a hollow steel spring, bent ac- 
cording to the Crosby Improved pattern, hardened and 
carefully drawn to spring temper, is substituted for the 
ordinary gage spring. In ordering, the maximum pressure 
to which they will be subjected should be stated ; and if the 
Tons on a Ram are required to be show^n on a second grad- 
uated circle, the diameter of the ram should also be given. 
No extra charge for second circle. Gages can be marked 
up to 20,000 lbs. per square inch, and warranted to stand 
any pressure indicated upon the dial. 



SIZES. 



No. 1, Brass Case, 814 in. Dial, 
it 2, «' " 6% 

♦* 3, " " 6 " 

" IV2, Iron '* 81/2 '' 
*' 21/2, " " 63/4 " 

" 31/2, *' •* 6 



1000 to 16,000 lbs. 
1000 " 10,000 " 
1000 ♦' 6,000 " 
1000 " 16,000 '* 
1000 " 10,000 " 
1000 *• 6,000 " 



These Gages are only made to order. 



Combination Pressure Gages. 

WE MANUFACTURE SEVERAL KINDS, AS FOLLOWS: 

— For Water Works. Graduated for pounds pressure 
per square inch and height of water in feet. 

— For Condensers. Graduated for pounds pressure 
per square inch and Vacuum in inches. 

— For Dentists, etc. Graduated for pounds pressure 
per square inch and Degrees of Heat. 

Sizes as per page 56. 



Test Gages. 

These Gages are highly finished in every particular. 
The movements are accurately adjusted and work smoothly. 
The dials are graduated in pound marks, tested by an 
open mercury column, and every instrument is fully war- 
ranted. 

Sizes as per page 56. 



SEND FOR ILLUSTRATED CATALOGUE. 



APPENDIX. 59 

CROSBY'S 
ADJUSTABLE POP SAFETY VALVE. 



One of the prime causes of boiler explosions is the 

gradual and insidious increase of the pressure of steam 

beyond the endurance of the boiler; but to every boiler 

there is a limit of pressure within which it is substantially 

safe. This point should be ascertained by hydraulic test 

annually, and no excess of pressure beyond this limit 

should be allowed at any time. The only sure pr(ventive 

is a safety valve which is all its name implies. The 

diameter of a safety valve is not an infallible test of its 
efficiency. A valve is effective in direct proportion to its 
lift, other conditions being equal. The higher the i^ressure 
of the steam, the less will a common safety valve lift; at 
most, its lift is very slight; and under its own action, with 
the increasing pressure of steam it will not increase suffi- 
ciently to relieve the boiler under all circumstances; but 
the pressure can .and may increase until an explosion 
occurs, while the valve is in operation. The co:nmon 
safety valve has much to answer for. Owing to the great 
friction of its parts, it will not open until the prtsfiure is 
above what it is set at; it will continue to blow a 'fer the 
pressure of the steam has fallen far below the point of 
opening; it wastes large quantities of valuable steam in 
operation. There are other grave faults, but these stated 
are sufficient to condemn it. Instead of standing guard 
over the boiler, a sentry has to be set over it, and sliould li«, 
by accident, ignorance or negligence, not properly attend to 
his duties, as is so often the case, especially in the use of 
portable boilers, the boiler is Avithout any safeguar.l what- 
ever. Hence the importance of any device which sUall re- 
duce the danger to its minimum. A safety valve which is 
automatic, certain in its action, prompt in opening and 
closing at the required points of pressure, and can be fully 
relied upon to relieve the boiler under all circumstances, is 
what is necessary. 

SEND FOR ILLUSTRATED CATALOGUE. 






60 APPENDIX. 

THE CROSBY 

Adjustable Fop Safety Valve, 

Affords all these qualities^ and experience and use have 
confirmed the following claims for it, namely : — 

1st — Opens precisely at fixed working pressure. 

2d — Discharges all excess of steam above fixed working 
pressure. 

3d — Reduces the pressure rapidly upon opening. 

4th — Closes with the least possible loss of steam. 

6th — The limits of pressure within which the valve will 
open and close are adjustable, 

6th — Uniform in action at different pressures. 

7th — Simple in arrangement and easily connected and ad- 
justed. 

8th — ^Does not deteriorate under continued use. 

9th — ^Never sticks on seat. 

10th — Makes comparatively little noise in discharging. 
11 th — Occupies less room than any other safety valve. 

SIZES. 



2 


*i 


2V4 

2% 


ft 
ft 


3 


ft 


1*A 


tt 
ft 


ft 


2 


ft 


2V4 


(( 


2V« 


(( 


3 


tf 


3% 


(( 


4 


<( 


5 


(( 



with Iro» Case and Lockup. 



tt <( 

tt tt 

it ft 

if ft 

it it 

it it 



it tt 

^ (( (( (( 

In ordering state what pressure valves shall be set at. If 
flange is required, state the diameter. 

SEND FOR ILLUSTRATED CATALOGUE. 



APPENDIX, 



61 




CROSBY'S ADJUSTABLE POP SAFETY VALVE. 



With Lock-up for Steamboat or Stationary Boilers. 
SEND FOR ILLUSTRATED CATALOGUE. 



fe2 



APPENDIX. 




*ii/is£xj. ct/f/ovA^osa/v sa 



CROSBY'S ADJUSTABLE POP SAFETY VALVE 

Half -SIZED cut of 2\ inch Locomotive Valve. 

SEND FOR ILLUSTRATED CATALOGUE. 



APPENDIX. 63 

This cut represents a 2i in. Yalve, as designed for 
locomotive use, half size. Each of these Yalves is tested 
under steam pressure, and set to open at the exact point 
of pressure desired, and is adjusted to close at about 
two pounds reduction ordinarily ; both of these points can 
be readily changed by the operator without removing it 
from the boiler or reducing steam. It is believed any 
person of ordinary intelligence will readily understand the 
principle and operation of this Yalve by the following 
description and explanation: 

The Yalve proper B B rests upon two flat annular seats 
Y Y and W W on the same plane, and is held down against 
the pressure of steam by the steel spiral spring S. The 
tension of this spring is caused by screwing down the 
threaded bolt L, at the top of the cylinder K. The 
area contained between the seats W and Y is what the 
steam pressure acts upon, ordinarily, to overcome the resist- 
ance of the spring. The area contained within the smaller 
seat W W, is not acted upon at all until the Yalve opens. 

The large seat Y Y is formed on the upper edge of the 
shell or body of the Yalve A A. The smaller seat W W is 
formed on the upper edge of a cylindrical chamber or well 
C C, which is situated in the centre of the shell or body of 
the Yalve, and is held in its place by four arms D D, radi- 
ating horizontally at right angles to each other, and connect- 
ing it with the body or shell of the Yalve. These arms 
are hollow and form four passages E E, for the escape of 
the steam or other fluid from the well into the air when the 
Yalve is open. This well is deepened so as to allow the 
wings X X of the Yalve proper to project down into it far 
enough to act as guides. The area of the apertures, at the 
outer ends of the passages through the arms, is reduced 
more or less at will, by screwing up or down the adjustable 
ring G G. 

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64 APPENDIX, 



Action of the Valve when Working Under 

Steam. 

When the pressure under the Valve is within about one 
pound of the maximum pressure required, the Yalve will 
open slightly, and the steam will escape under the larger 
seat into the cylinder surrounding the spring, thence into 
the air; the steam is also forced mider the smaller seat into 
the well and thence through the passages in the arms into 
the air. As soon as the pressure attains the exact maximum 
point, the Yalve will be lifted so high as to force the steam 
into the well faster than it can escape through the apertures 
in the arms; a pressure will then accumulate under the 
inner seat, which will be in excess of what was required to 
overcome the increasing resistance offered by the spring, 
and acting upon the additional area presented, at once 
forces the Yalve wide open and rapidly relieves the boiler. 
This pressure under the inner seat is of itself differential. 
The Yalve then at once slowly settles down and the pres- 
sure under the inner seat as slowly diminishes, and so con- 
tinues until the area of the opening under the smaller or 
inner seat is less than the area of the apertures in the arms 
for the escape of the steam ; the pressure then ceases and 
the Yalve promptly closes. The point of opening can be 
readily changed while under steam by screwing the 
threaded bolt at the top of the cylinder, either up or down ; 
and the point of closing is as easily adjusted by screwing 
up or down the ring surrounding the outside shell or body 
of the Yalve. The seats of this Yalve are flat and do not 
wear out and leak so readily as beveled seats. 



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APPENDIX. 65 

Crosby's Self-Regulating Reducing Valve. 

This Valve was produced to meet an important want, 
i. e.y to reduce the pressure of direct steam, gas, or other 
fluid taken from a boiler or generator, to a lighter pressure 
in the pipes or apparatus for manufacturing or heating 
purposes, and maintaining such pressure constantly, not- 
withstanding the variation that may take place in the 
boiler above the pressure required. The operator can re- 
adjust at will by simply turning the screw upwards for in- 
creased, and downwards for diminished pressure, and a 
steam gage attached through the nut on top of the valve will 
indicate the pressure which the valve is supplying. It is 
adapted for use in Distilleries, Sugar Refineries, Bleacheries, 
Paper Mills, and for reducing and regulating the pressure 
of steam supplied from boiler or street mains to dwelling 
houses, etc., and steam heating in general, or wherever a 
constant unvarying pressure is required. We make the 
following claims as to its qualities and capacity, which are 
being confirmed daily, viz. : 

1st. Certainty and nnifonnity of action at different pressures. 

2d. Simple in arrangement, easily connected and adjusted. 

3d. Compact, occupying no more space than a G-lobe Valve. 

4tli. Does not deteriorate under continued use. 

5tli. No outside leakage or drip. 

6tli. Works without Diaphragm or Rubber. 

7th. No Stuffing boxes to take care of. 

8th. Costs less than any other Eegulating Valve. 

SIZES, 
For 1/^ inch Pipe, i For 2 inch Pipe. 

(< 8/ (( (( "3 '^ *' 

" 114 " *' I "5 " " 

CROSBY STEAM ENGINE INDICATOR. 

Each Indicator is equipped with one Spring, tscale, Elbow 
and Cock ; also, two quires of metallic paper, bottle of watch 
oil, screw-driver and wrench, and is neatly fitted into a 
velvet-lined walnut case, with nickel handle, hinges, hooks, 
and lock and key. 

Directions for using the Indicator and a few general 
rules for reading and measuring diagrams accompanies the 
whole. When requested, any extras, such as Proportional 
Dividers, Telescope-Connection, Carrjdng Pulleys, Clamps, 
or any extra Springs, Scales, Elbows, Cocks, Paper or Oil, 
will be furnished as such. 

N. B. A hinged snap-lever for holding the paper on the 
cylinder is supplied instead of the ordinary springs for that 
purpose, when especially ordered. 

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66 APPENDIX. 



Engine Revolution Counters 

These instruments are made upon an improved plan, 
taken from a German device used for another purpose, and 
are in many respects superior to, and more durable than 
any other. The mechanism is very simple and will not 
readily get out of order. The running parts are all made of 
iron or steel, and so less liable to wear. Every counter 
fully guaranteed. Sizes as follows : 

10 in. Dial, _ _ _ _ - Brass Case and Ring. 

81/2 ** ------ *' " " 

6% '' ----- '^ «« ii 

Counter Movement witliout Case, - - 2 in. and 2l^ in. 
Pedestals furnished when ordered. 



Marine Clocks. 

The movements in these Clocks are very superior, are 
fitted with the Patent Kegulator and Chronometer Balance, 
are full jewelled and warranted. 

SIZES, 



10 in. Dial, 
634 - ^ 


- 1 or 8 Day. 

_ _ a 

Pedestal furnish 
Cases Fitter! witi 


6 in. Dial, - 

51/2 - . - - 

41/2 " - - 
ed when ordered. 

h a Lock and Key, 


1 or 8 Day. 



Test Pumps. 

SIZES AND STYLES. 

Small Screw (Inspector's). Large Screw, with stand. 

Large Lever, with table. 



Crosby's Safety Water Gage. 

A very simple device, which does not alter the external 
appearance of the water gage and enhances its value greatly. 
Its action is so complete, that upon the sudden breaking of 
a glass tube not a drop of either steam or water is percepti- 
ble, other than was in the glass at the moment of breaking. 

SEND FOR ILLUSTRATED CATALOGUE. 



APPENDIX. 67 

The " Victory'* Lubricator, 

For Oiling the Valves and Cylinders of Steam Engines. 
For Effectiveness, Economy and Reliability, this Lubri- 
cator is without a rival. It embraces the remarkable fea- 
ture of SIGHT FEEDING, which enables the engineer to set 
the proper feed at once, relieving him from the necessity of 
GUESSING the rate at which his lubricator is feeding, or 
whether it is feeding at all. 

In this Lubricator the oil is seen passing to the engine in 
drops, and may be regulated to deliver even less than one 
drop a minute, while uniform and certain action is still 
secured. 

SIZES. 
Quarter Pint. One Quart. 

Half Pint. Half Gallon. 

One Pint. One Gallon. 



Crosby's Improved Pyrometer. 

Adapted for Blast Furnaces, Hot Air Pipes, Superheated 
Steam, Varnish Kettles, Tempering Ovens, Baker's Ovens, 
Drying and Japan Ovens, Oil and Tar StiUs, Galvanizing 
Baths, Wire Annealing, Chimneys, etc. 

This Pyrometer correctly indicates Temperatures to 1200 
degrees Fahrenheit by the expansion of its Metallic Stem. 
Each instrument is carefully graduated to a standard, and 
is fully warranted to the highest Temperature marked upon 
its dial. 

SIZES. 

Iron Case and Brass Ring. 



5 inch Dial, 


6 


i 


' 


6% 

8% 




i 


5 




i 


6 


t 


< 


63/4 


. 


(( 


8y2 




< 



Brass Case and Ring, 



THERMOMETERS OF ALL KINDS. 



Salinometers. 

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68 APPENDIX. 

Crosby^s Low Water Alarm. 

This instrument works automatically and irresistibly 
without the use of Fusible Plugs, Floats, Cranks, Springs, 
or other moving machinery, and no part need be removed 
or readjusted to fit it for work again after its action. Is 
simple, reliable, cheap and durable. 



Open Mercury Columns. 

Delicately graduated and warranted coiTect, 



Siphons, for Steam Gages- 
improved Brass Siphon and Cock combined, non-freezinj 
♦' " " without Cock, '• 



Cocks, for Gages. 

STYLES, 

Large and Small Common Cocks, with T handles. 

Large and Small Union Cocks, Lever or 'J' handles. 



Gage Cocks. 

With or ivithout Self Cleaning Attachment. 



Steam Whistles. 

STYLES, 

No. 1, without valve. No. 2, with upright valve. No. 3, with side valve. 
Chime whistles, of any number or size of Bells required. 



Whistle Valves. 



Scotch Glass Tubes 



American Glass Tubes 

Any size or length to order. 
SEND FOR ILLUSTRATED CATALOGUJi 



APPENDIX. 



69 



U. S. GOVERNMENT APPROVAL. 

Our Gages and Yalves have been approv^ed and adopted 
by the board of U. S. Supervising Inspectors of Steamboats 
and the Secretar}' of the Treasury. 

The Committee of U. S. Supervising Inspectors, appointed 
to test Safety Valves, state in their printed Report to the 
Board: *' that they have no hesitancy in report- 
ing THAT AMONG THE VERY EFFICIENT INSTRUMENTS 

THE Crosby was one of the most efficient;'' 
and that *' upon the first trials an excess was 

OBTAINED, BUT THIS WAS ONLY TEMPORARY ; AND 
UPON A TRIAL AFTER RE-ADJUSTMENT, NO EXCESS WAS 
OBTAINED." 

A tabulated report of which is as follows : 







CO 


1o 


'6 
o 

Q 




5 in. 





68-2 


70 


671-2 
68 


Opened and closed fire times in 1 min. 


10 in. 





69 


70 


u ». «. ten ** 10 " 



*' Movement of Opening and Closing very- clear 
and points well defined. 
Actions steady^ 
Opening promptly. 
Closing promptly." 



SEND for illustrated CATALOGUE. 



INDEX. 







PAGES, 


Admission Line .... 




15, 24, 26 


^^ ^' Explanation of 




. 26 


Air-pump, Efficiency of . 




. 16, 29, 30, 38 


Appendix 




54-70 


Atmosphere, Density of . 




. 38 


Atmospheric Pressure 




. 20, 24, 25, 28, 38 


Line . . . . 


20, 


24, 25, 35, 36, 37, 38 


'' '' Explanation of 




. 25 


" '' Measuring from 




. 31, 35, 36, 37, 38 


Average Pressures . . . . 


15, 


23, 32, 34, 35, 37, 40 


To Compute . 




. 32, 34 


Boiler, Steam furnished by 




. 15, 27, 31, 42 


'' Pressure . . . . 




15, 21, 27, 30, 31, 42 


Line . 




. . 24, 30, 31, 


Clearance . . . .21, 


24, 


31, 32, 33, 34, 41, 42 


'* Contents of . 




21, 31,*32 


** To be added to Diagram 




. 31, 32, 33, 34, 41 


** Line . . . . 




24, 31, 32, 33, 34, 42 


** " Explanation of . 




. 31 


^* ^* Measuring from . 




. 31, 32, 33, 34, 42 


Compression . . .15, 16, 


24, 


26, 30, 35, 36, 38, 42 


" Average . 




. 30,42 


" Line . . . . 




24, 30, 42 


'' '' Explanation of 




. 30 


Cord, Indicator . . . . 




10, 11, 12, 18, 19, 20 


*' Point on Engine to Connect . 




. 18 


Condenser, Efficiency of . 




. 16, 29, 30, 38 


Counter-pressure . . . . 


15, 


24, 28, 29, 35, 36, 38 



n 



INDEX. 



Counter-pressure Line, Explanation 
Crosby's Improved Indicator . 



Description of 
Directions for Using 



PAGKS. 

. 29 
8, 9, 17 
. 8 
. 17 
. 30 



Cushioning, Explanation of . 

Cut-off, Point of ... . 15, 27, 28, 29, 32, 33, 34 

'• Pressure at 15,23,27 

Cylinder, Dimensions of Engine .... 21, 31 
Diagrams from each end of . . 14, 21, 23, 24 
Discharge Passages from . . 15, 24, 29 

Drilling and Connecting with . . .17 
Indicator .... 10, 13, 20, 21 , 22, 32 

Name of ends of 21 

Paper ...... 10, 19, 20 

Pressure in 

5, 14, 15, 16, 20, 23, 25-30, 32, 34-38, 41, 42 
Scratches on Indicator Piston or . . . 22 
Steam consmned in . . 15, 16, 31, 41, 42 

^* Passages between Boiler and 15, 24, 26, 27 
Disideratum, or the important thing . . . .25 

Diagrams, 23 

'' as Exponents of Steam Engines, 

5, 6, 15, 16, 23, 25, 42 
Causes which determine figures of 5, 25, 24, 29 
Clearance to be added to .31, 32, 33, 34, 41 
Divisions or Spaces of . 
Difference in . 



Errors in Keading 



'^ Measuring 



*^ of Registration on 7, 
Explanation of Lines of 
Examples of . 
Features of Merit or Defect' 
Form of . 

Friction .... 
from each end of Cylinder 



33, 34,36, 37, 38 

23, 24, 25, 29, 41 

5 

5, 36 

12, 13, 17, 19, 23, 29 
24-34 
45-53 
25-34 
. 5, 7, 23, 25 
16, 25, 39, 40, 41 
. 14, 21, 23, 24 



INDEX. 



Diasrrams, How to take 



Instrument for Spacing 

Indicator, 

Loops on , . . 

Lines of . . 23, 24-34, 

Memoranda on 

Methods of Measuring . 



28, 
35, 36, 



*' Names of Lines 

"" Paper used for 

'• Reading .... 

^' Serrated Lines on . 

" Upper and Lower Lines of 

Dividers, Proportional 
Drum. Indicator .... 
Errors of Calculation 

'• Measurement . 
" Reading .... 
'* Registration . . .7, 
Examples of Computation 
^' Diagrams . 

Exhaust Line . . , . . 
^' " Exj)lanation of 

'' Yalve, Condition of 15,17,23, 
Expansion, Apparatus for Procuring 
" Economy of . 

" Law of . 

'' Line, . . 24, 27 

" '^ Explanation of 

'' " Theoretic 

Friction Diagrams . 

'* of Steam Engine 
Gage, Steam . 
'' Vacuum 
Horse-power, Definition of Term 

'^ see Power of Steam Engine 

Hook and Running Loop 



28, 



5,1 



24 



12,1 



27, 28, 



32, 



111 

PAGES. 
. 19 

. 34 

23, 25, 42 

30, 36, 37, 38 

37, 38, 41, 42 

. 21 

35, 36, 37, 38 

. 24 

14, 19, 21, 23 

. 5, 23, 36 

7, 22, 26, 29 

35, 36, 37, 38 

. 34 

10, 12, 19, 20 

5 



5,36 



17, 19, 23, 29 

. 43, 44 

45-53 

24, 29, 37 

. 29 

29, 30, 32, 33 

. 16, 32 

. 16 



16, 



35, 36, 37, 38 

. . 27 

27, 28, 32, 33 

25, 39, 40 

25, 39, 40, 41 

17, 25, 30, 31 

. 21 

. 39 

. 40 

. 19, 20 



IV 



INDEX. 



PAGES. 

Improvements in Indicator 6, 7, 8 

Indicator, Advantages resulting from Use of 5, 6, 9, 13, 39 
" Crosby's Improved . . . . 8, 9, 17 



a 



Cord 

Condition of . 
Cylinder, 
Description of 
Diagrams, 
Direct-acting . 
Directions for Using 



10, 11, 12, 18, 19, 20 

. 22 

10, 13, 20, 21, 22, 32 

. 8 

23, 25, 42 

. 6 

. . . 17 



Facts Ascertained by Use of 

5, 6, 15, 16, 23, 25, 39, 40, 42 
For High Speed or Pressure . . . 6, 8, 14 



How to Attach 


. 17 


How to Take Apart and Clean 

'' " "2, Diagram with 
Improvements ... 
McNaught's . . . . 


. 21 
. 19 

. . 6,^7, 8 
. 6 


Kichards' .... 


. 7 


Reciprocating Parts of . 


6, 7, 12, 13, 26 



** Multiplication of Piston Motion of . 6, 7, 13 

'' Oil for Lubricating . . .12, 16, 21, 22 

** On Locomotives 41 

** Original Inventor of 6 

" Parallel Motion for .... 7, 8, 13 

** Piston, . . 7, 8, 10, 12, 13, 20, 21, 22, 23, 25 

Piston-rod . . . .10, 11, 12, 13, 22 
" Self-lubricating .... 11, 12, 13 

" Simplicity of Operating Crosby's . . 13, 14 

'' Springs . . 6, 7, 10, 11, 12, 19, 21, 22, 29, 35 

^' Superiority of Crosby's . . . . 13, 14 

" The Steam Engine . . . . . 5, 6 

'' Watt's . . , 6 

Introduction, 3 

Law of Expansion 32 

Lines, Admission 15, 24, 26 



INDEX. 



Lines, Atmospheric . 
'* Boiler Pressure 
** Clearance 
^' Counter-pressure 
" Compression . 



PAGES. 

20, 24, 25, 35, 36, 37, 38 

24, 30, 31 

24, 31, 32, 33, 34, 42 

. 24, 29 

24, 30, 42 



Errors in Registering, Reading and Measuring 

5, 7, 12, 13, 17, 19, 23, 29 

Exhaust 24, 29, 37 

Expansion . . 24, 27, 28, 32, 33, 35, 36, 37, 38 
Explanation of 24-34 



m 



23, 24 



-34, 



24. 



** Forming Loops 
** Features of Merit or Defect 
'' Hair 
'^ Indellible 
" Names of Diagram 
*' of Diagram . 
** Reading Diagram . 
*^ Serrated 
'' Steam . 
*' Theoretic Expansion 
^^ Upper and Lower . 
** Vacuum 
*^ Variable or Double 
'' Wavy . 
Loops on Diagrams . 

"" Running 
Lubi-icating, Oil for 
Self . 
McNaught's Indicator 
Measuring Clearance 
" Diagrams 

** from Vacuum Line 

** '^ Atmospheric Line 

^^ Steam Consumed in Cylinder 

Oil for Lubricating . 
'* Reservoir in Piston-rod 



28, 30, 36, 37, 38 

25-34 

11, 14, 20 

. 23 

. 24 

35, 36, 37,38,41,42 

. 5, 23, 36 

. 7, 22, 26, 29 

26, 27, 33, 34, 35, 36 

24, 27, 28, 32, 33 

24, 35, 36, 37, 38 

^4, 31, 33, 36, 38, 42 

. 29, 41 

. 29 

28, 30, 36, 37, 38 

19, 20 

. 12, 16, 21, 22 

11, 12, 1:5 

... 6 

31, 32, 33, 34, 42 

23, 29, 35, 36, 37, 38 

31, 33, 36, 38, 41, 42 

31, 35, 36, 37, 38 

15, 16, 31, 41, 42 

. 12, 16, 21,22 

11, 12 



VI 



INDEX. 



Papei^, Common and Silica finish 

Parallel Motion 

Pencil, Adjustment of . . 

*' Metallic and Graphite 

^' Oscillation of 

" Travel of . 
Piston, Area of . . . 

Indicator . . 7, 8, 10, 12, 13, 20, 21, 22, 23, 25 

'' Pressure on 5, 14, 15, 16, 20, 23, 25-30, 32, 34-38, 41, 42 

" Proper fitting of . . . 15, 23, 27, 28, 29, 32, 33 

" Speed of 
Piston-rod, Area of Engine 
** Indicator 



PAGK.-^. 

5, 11, 14, 19, 21, 2S 

. 7, 8, 13 

11, 12, 13, 20 

. 11, 23 

6,29 

. 14 

21, 40, 41, 42 



6, 8, 24, 25, 26, 29, 40, 42 

. 21,41 

. 10, 11, 12, 13, 22 

11, 12 

. . .11 

16, 41 



'* Hollow . 
'^ Oil Reservoir in 
Power Consumed by Tenants 

Horse 39, 40, 43, 44 

'' Lost . . 16, 25, 28, 29, 30, 36, 37, 38, 39, 40, 41 

'' Nominal, Actual and Effective . 39, 40, 41, 43, 44 

of Steam Engine ... 23, 29, 39, 40, 43, 44 

" to Drive Machinery 16, 41 

" to Overcome Friction of Engine 

16, 25, 39, 40, 41, 43, 44 

Pressure, Atmospheric . . . . 20, 24, 25, 28, 38 

Average .... 15, 23, 32, 34, 35, 37, 40 

at Point of Cut-off . . 15, 27, 28, 29, 32, 33, 34 

" '' " Release . 15, 25, 29, 34, 40, 42 

" ** any Point in Stroke 

5, 15, 16, 20, 23, 26-30, 32, 33, 34, 40, 42 
Boiler . . . . 15, 21, 27, 30, 31, 42 



Counter . 

Effective . 

Impelling 

Initial 

of Pencil upon Paper 

Resistinsr . 



15, 24, 28, 29, 35, 36, 38 
25, 36, 37, 38, 40 
. 28, 30, 35, 37 
26, 27, 40 
. 11, 13, 14, 20 
28, 30, 35, 36, 37, 38 



INDEX. 



Vll 



Pressure, Scales for various . 

" Springs '' . 6, 7 

** Steam . . 5, 14 

** Terminal . 
' ' To Compute Average 
'^ Vacuum (so-called) 
Proportional Dividers 
Reciprocating parts of Engine 

** ^* Indicator 

Richard's Indicator . 
Scales, Graduated Indicator . 
Scratches on Indicator Cylinder or 
Serrated Lines on Diagram 
Snap-latch .... 
Springs, Adjusted Drum 

*^ Graduated Indicator . 6, \ 
" Other Indicator . 
Steam Consumed by Engine . 
Engine, Area of Piston of 
'* '' Piston-rod of 

" Computing Power of 
^* Condition of . 



PAGES. 

21, 30, 31, 33, 35, 38 

10, 12, 14, 21, 22, 29, 35 

15, 26, 27, 30, 34-38, 40 

15, 25, 29, 34, 40, 42 

. 34, 35, 43, 44 

14, 16, 21, 31, 37, 38 

. 34 

. 21 

6, 7, 12, 13, 26 

7 

21, 30, 31, 33, 35, 38 

Piston . . .21 

. 7, 22, 26, 29 

. 19 

. 11 

12, 14, 21, 22^29, 35 

11, 19 

15, 16, 31, 41, 42 

. 21, 40, 41, 42 

. 21, 41 

40, 43, 44 

. 5, 15, 23 



10, 



Condensing 16, 21, 24, 25, 28, 29, 37, 38, 40 
Cylinder 14, 15, 16, 17, 21, 23, 26, 27, 32, 33 
Different Diagrams from same 25, 29, 41 
Exponent of . 5, 6, 15, 16, 23, 25, 39, 40, 42 
Friction of . . .16, 25, 39, 40, 41 

Indicator 5, 6 

:N'on-condensing . 24, 28, 29, 35, 37, 38 
Power of .... 23, 29, 39, 40 

Reciprocating Parts of . . . .21 
Regularity of Speed of . , , .41 
Revolutions of . 20, 21, 24, 29, 41, 42 
Speed of Piston of 6, 8, 24, 25, 26, 29, 40, 42 
Strokes of " 
5, 15, 16, 19, 21, 25, 26, 27, 80, 33, 35, 37, 40, 42 



Vlll INDEX. 

PAGKS. 

Steam Engine, Style of 21, 25, 35, 36 

Steam, Expansion of . . 6, 16, 27, 28, 29, 32, 33, 34 
" Gage, Accnracy of .... 17, 25, 30, 31 

*^ Line 24, 26, 27, 33, 34, 35, 36 

*' Explanation of 27 

Lost 15, 27, 28 

'' Pressure of . . 5, 14, 15, 26, 27, 30, 34-38, 40 

Tenants, Power Consumed by .... 16, 41 

Theoretic Curve or Isotliermal Line . 24, 27, 28, 32, 33 

" How to Draw . , . . , . 33 

Yacuum . . 14, 16, 21, 24, 29, 31, 33, 30, 37, 38, 41, 42 

'' Average 16, 37 

Perfect 24, 31, 33, 38, 41 

'' Gage 21 

'' Line 24, 31, 33, 36, 38, 42 

'' '' Explanation of 31 

" '' Measuring from . 31, 33, 36, 38, 41, 42 

Yalves, Condition of . 15, 17, 23, 27, 28, 29, 30, 32, 33 

" Exhaust 17, 23, 28, 29, 30 ' 

Watf s Indicator 6 

Wavy Lines 29 



